Attachment for wood-boring braces.



No. 813,070. PATENTED FEB. 20, 1906.

D. B. YODER. ATTACHMENT FOR WOOD BORING BRAOES.

APPLICATION FILED JULY 18, 1905.

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No. 813,070. PATENTED FEB. 20, 1906. D. B. YODER.

ATTAOHMIEINT FOR WOOD BORING BRAGES. APPLICATION FILED JULY 18, 1905.

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I i I IzT-fl- H gluoowbo'a wat m a I wawf jh M atto'nnu k DAVID B.YODER, OF GUTHRIE, OKLAHOMA TERRITORY.

ATTACHMENT FOR WOOD-BORING BRACES.

Specification of Letters Patent.

Patented Feb. 20, 1906.

Application filed July 18,1905. Serial lTox 270,174.

To aZZ whom it may concern:

Be it known that 1, DAVID B. YODER, a citizen of the United States,residing at Guthrie, in the county of Logan, Oklahoma Territory, haveinvented new and useful Improvements in Attachments for VVood-BoringBraces, of which the following is a specification.

My invention is an attachment foran ordinary wood-boring brace to enablethe latter to be used for drilling metal; and it is characterizedparticularly by the adaptation of the ordinary clamping-sleeve as ameans for feeding the work to the drill in addition to its ordinaryfunction of clamping the jaws. This is done, too, in such manner thatany friction or pressure due to the feed tends to tighten the grip ofthe jaws on the shank of the bit or drill.

The invention is illustrated in the accompa nying drawings, in whichFigure 1 is an elevation of the brace, showing the application of theinvention thereto. Fig. 2 is a central vertical section. Fig. 3 is asection at right angles to that of Fig. 2.

Referring specifically to the drawings, 4 denotes the U-crank arm of anordinary woodboring brace. The bit 5 is held by means of jaws 6, whichare carried within grooves in the sides of the spindle 6 of the brace,on which the clamping-sleeve 7 turns. The spindle is formed integralwith a ring 6, at the outer end thereof. The inner ends of the jaws haveteeth 6 which extend through the slots to engagement with screw-threadson the inside of the sleeve, whereby the jaws are drawn in or forced outto grip or release the bit when the clamping-sleeve is turned in onedirection or the other. The sleeve 7 is rotated to open or close thejaws by a finger piece or ring 8, which is rotatably mounted on thespindle and has a projecting stud 19, which fits in a notch 20 in theupper end of the sleeve. This finger-piece is used for the sake ofconvenience, because the barrel would be difficult or inconvenient tograsp and hold by hand.

At 8 is indicated a ring having projecting arms 9, which receive thefree ends of a chain 10, passing around the work to be drilled. The ring8 fits loosely on a sleeve 11, having a threaded bore 12. The sleeve 7is threaded externally, as at 13, andreceives the sleeve 11. The threadsare fine to give the requisite slow feed, and are opposite in directionto the inner threads, so that the strain of the feed tends to tightenthe jaws. The lower end of the sleeve 11 is formed with anoutwardly-extending flange 14, and the opposite end is externallythreaded, as at 15, to receive a screw-ring 16. The ring 8 fits looselyon the sleeve 11- between the flange 14 and the ring 16.Antifriction-balls 17 are placed between the parts to enable the ring 8to turn freely on the sleeve 11, the parts being held together by thering 16.

In operation as a drill the parts are arranged as shown in Fig. 1 andthe crank is turned to drive the drill. If the parts be allowed to runfree, the ring 14 will turn with the spindle and sleeve, the resistanceor friction therebetween being greater than thefric tion between therings 11 and 8, particularly in consequence of the ball-bearings; but ifthe ring 11 be held by hand against rotation it will travel up on thethread 13 in consequence of the rotation of the crank and draw the drillto the work, thus providing an automatic and power feed. The feed can beinstantly stopped by releasing the ring 11.

The attachment can remain on the brace when it is to be used for boringwood by removal of the chain 10. It is therefore handy and convenientand at all times ready for use as either a drill or brace.

The parts herein described can be readily applied to any ordinarywood-boring brace, no specially-constructed brace being required. Theonly change necessary is to cut a thread on the sleeve which operatesthe jaws and apply the rings thereto.

I claim 1. The combination with the jaw-clamping sleeve of aboring-brace, said sleeve being threaded externally and driven by theordinary rotation of the brace, of an internallythreaded member workingon said sleeve, and a clamping-chain, the ends of which are carried bythe aforesaid member.

2. The combination with the jaw-clamping sleeve of a boring-brace, said.sleeve being threaded externally and rotated by the ordinary rotation ofthe brace, of an internallythreaded member working on said sleeve, arotatable ring carried by the aforesaid member, and a clampingchain, theends of which are secured to the ring.

3. The combination with a boring-brace having a j aw-clamping sleeverotatable with the spindle of the brace, said sleeve being threadedexteriorly, of an internally-threaded inner ring on said sleeve, thethreads being arranged to cause the ring to travel inwardly When thebrace is turned to drive the bit or In testimony whereof I have signedmy drill, an outer ring rotatably mounted on said name to thisspecification in the presence of .10 ring and having a clamping-chainattached two subscribing Witnesses.

thereto, and antifriction-bearings between the rings constructed to giveless friction DAVID YODER' therebetween than between the sleeve andWitnesses: the inner ring, so that normally the sleeve R. R. CARLIN,

and the inner ring turn together. D. STEVENS.

